The high detectability of oil fluorescence has frequently been utilized as a means for monitoring oil spills and for prospecting for oil and gas. In drilling for oil and gas, samples of mud, drill cuttings, and cores are often examined under ultraviolet light for evidence of fluorescence due to small quantities of hydrocarbons. This is discussed by R. G. Swanson in a sample examination manual entitled Methods in Exploration published by AAPG, (1981). To determine the types and concentrations of oils, several techniques of fluorescence spectrophotometry are available for recording fluorescence spectra of oils (excitation wavelength vs emission wavelength vs fluorescence intensity). Several examples of applications utilizing fluorescence spectrophotometry techniques exist. One use of fluorescence spectrophotometry is for monitoring the source of an oil spill on water. This use is mentioned in U.S. Pat. No. 3,899,213 which issued on Aug. 12, 1975. It is also discussed in an article by A. D. Thruston and R. W. Knight entitled "Characterization of crude and residual-type oils by fluorescence spectroscopy" which appears in Environ. Sci. & Tech., v.5/1, pp. 64-69 (1981).
Another use of fluorescence spectrophotometry is for oil and gas prospecting via remote sensing or near surface sampling methods. A discussion about this use appears in U.S.G.S. Open-File Report 84-385, 34 pp (1984) in an article by M. E. Henry and T. J. Donovan entitled "Luminescense properties and chemical composition of crude oils." Fluorescense techniques have also been used for geochemical prospecting. This is discussed by C. F. Hebert in an article entitled "Geochemical prospecting for oil and gas using hydrocarbon fluorescence techniques", 3rd Southern Methodist Univ. Symp. Unconventional Methods in Exploration for Petroleum and Natural Gas. Proc., pp. 40-58 (1984).
A third utilization of fluorescence spectrophotometry is for delineating the path of oil migration. This utilization is discussed in an article by R. E. Riecker entitled "Hydrocarbon fluorescence and migration of petroleum" which appeared in AAPG Bulletin, v.46/1, pp. 60-75 (1962).
Fluorescence spectrophotometry is used also in evaluating oil-oil and oil-source rock correlations. See "Oil-oil correlations by fluorescence spectrophotometry", Am. Chem. Soc. 181st National Mtg. Abstract, Division of Geochemistry, paper no 25, by G. G. Janezic et al. (1981). Also see "Applications of total scanning fluorescence to exploration geochemistry", 15th Offshore Technology Conf. Proc., v.3., pp. 393-400, by M. J. Brooks et al., (1983).
The aforementioned fluorescence techniques, however, require a relatively large amount of oil sample (u/cc). To measure the fluorescing characteristics of micro-sized fluorescing matter, a method wherein microscopy is combined with fluorescence spectrophotometry is required. Fluorescence microspectrophotometry is used in the studies of fluorescing organic matter in coals. One study is entitled "Spectral fluorescence measurements of sporinites in reflected light and their applicability for coalification studies" as published in Petrographic Organique et Potential Petrolier, CNRS, Paris, pp.49-65 by K. Ottenjann et al. (1975). Another study is entitled "Application of fluorescence microscopy in coal petrology and oil exploration", Jour. Microscopy, 109(1), pp. 49-73, M. Teichmuller and M. Wolf (1977). Further use of fluorescence microspectrophotometry in coal studies is disclosed in an article by H. Hagemann and A. Hollerbach entitled "Spectral fluoromatic analysis of extracts - a new method of the determination of the degree of maturity of organic matter in sedimentary rocks, Bull. Centres Rech. Explor.-Prod., Elf-Acquitane, v.5/2, pp. 635-650 (1981). M. Teichmuller and B. Durand have disclosed studies on coals as evidenced in an article entitled "Fluorescence microscopical rank studies on liptinities in peat and coals, and comparison with results of the rock-eval pyrolysis, Int. Jour. Coal Geo., V2, pp. 197-230 (1983).
Fluorescence microspectrophotometry has also been used in the studies of oils trapped as micro-sized inclusions in rocks from sedimentary basins. R. K. McLimans in an article entitled "Migration and maturation of hydrocarbons-evidence from fluid inclusions", AAPG Bull., v.69/2, p. 286 (1985) reported the occurrence of oil-filled inclusions that have different fluorescence spectra in the same crystals. W. Visser in a Chemical Geology publication, currently in press, entitled "Oil inclusions in sedimentary rocks", documented the relationship between fluorescence and oil density for a suite of oils from the Maracaibo Basin in Venezula.
To date, no one has sought to combine microscopy and fluorescence spectrophotometry as a means to estimate the oil quality in undrilled petroleum basins or areas of new exploration plays.